Analysis of Wave Height in Front of a Wave Absorbing Structure with Rubble Foundation   总被引：1，自引：0，他引：1  

Li Rongqing Xie Shileng Engineer  The First Design Institute of Navigation Engineering  The Ministry of Communications  Tianjin Professor  Senior Engineer  Deputy Chief Engineer  The First Design Institute of Navigation Engineering  The Ministry of Communications  Tianjin 《中国海洋工程》1992,(3)

Wave absorbing structures have been widely applied in many countries. In the present paper, the wave heights in front of a vertical wave absorbing structure with rubble foundation as well as in the wave chamber of the structure are analysed using an approximative calculation method, and the dissipating effect of the structure is verified. On the basis of the results of regular waves, the relative wave heights of irregular waves in front of the wave absorbing structure as well as in the chamber have also been analysed.  相似文献   

Ultimate Bearing Capacity of Subsoils to Marine Pipelines     

Yan Chi  Zhang Jianguo  Yan Shuwang Lecturer  Dept. of Hydraulic Eng.  Tianjing University  Tianjin Professor  Dept. of Hydraulic Eng.  Tianjing University  Tianjin 《中国海洋工程》1994,(4)

- Based on the theory of limit analysis, the Finite Difference Method (FDM) is established for evaluating the ultimate bearing capacity of subsoils to bear the unburied pipelines. The analytical results of bearing capacity of the ideal clay is given. The approach to bearing capacity evaluation of cohesionless subsoils without surcharge is suggested. The results from this method are consistent with those obtained from model tests.  相似文献   

Dynamics of Sea Ice and Spectrum of Ice Force     

Shi Qingzeng  Chen Xing Professor  Dept. of Ocean Eng.  Naval Arch  Tianjin Univ.  Tianjin Lecturer  Dept. of Ocean Eng.  Naval Arch.  Tianjin Univ.  Tianjin 《中国海洋工程》1995,(2)

Spectrum and self-excite characters are the two significant characters of the dynamics of sea ice. The spectrum character of sea ice is mainly shown by the spectrum of ice force. The spectrum character of the sea ice is its intrinsic attributes. When the spectrum of ice force from the dynamic response of ice and structure interaction are evaluated, the effect of dynamic character of the structure must be eliminated. In this paper, the ice force spectrum at Bohai Bay and Liaodong Bay is evaluated from the displacement and strain responses of a single degree and a multi-degree freedom structure. The evaluated ice force spectrum can be used to define the spectrum character of ice in the analysis of ice induced vibration.  相似文献   

Application of Random Process in Soil Profile Modeling     

Yan Shuwang  Jia Xiaoli  Deng Weidong Professor  Dept. of Hydraulic Eng.  Tianjin University  Tianjin Graduate student  Dept. of Hydraulic Eng.  Tianjin University  Tianjin Senior Engineer  Chongqing Institute of Highway Science 《中国海洋工程》1994,(4)

When using the random process in soil profile modeling, the stationary and ergodicity of thesoil properties in the profile must be tested. This paper describes a procedure for stationary and ergodicity testing. Numerical examples were given for demonstration. A log-cosine function is suggested to simulate the correlation function, which has been proved to be good for soil profile modeling.  相似文献   

Perturbation Analysis of the Attached Water Mass Effect on Offshore Platform Dynamic Response     

Chu Liangcheng  Qu Naisi  Guo Yonggang  Lu Min Ph.D.  Dalian University of Technology  Dalian Associate Professor  Dalian University of Technology  Dalian Assistant  M.S.  Dalian University of Technology  Dalian Engineer  Bohai Oil Company  Tianjin 《中国海洋工程》1993,(4)

- Theoretically speaking, it is impossible to make the differential equation of motion uncoupled for the natural modes of a system in consideration of the attached water. The hydro-elastic structure is equal to the, non-proportional damping system. In this paper a perturbation analysis method is put forward. The structure motion equation is strictly solved mathematically, and the non-proportional damping problem is transformed into a series of proportional damping ones in the superposition form. The paper also presents the calculation formula of the dyanamic response of the structure being subjected to harmonic and arbitrary load. The convergence of the proposed method is also studied in this paper, and the corresponding convergence conditions are given. Finally, the proposed method is used to analyze the displacement response of a real offshore platform. The calculation results show that this method has the characteristics of high accuracy and fast convergence.  相似文献   

Experimental Researches on Reflective and Transmitting Performances of Quarter Circular Breakwater Under Regular and Irregular Waves     

史艳娇  吴米玲  蒋学炼  李炎保 《中国海洋工程》2011,(3)

A series of regular and irregular wave experiments are conducted to study the reflective and transmitting performances of quarter circular breakwater (QCB) in comparison with those of semi-circular breakwater (SCB). Based on regular wave tests, the reflection and transmission characteristics of QCB are analyzed and a few influencing factors are investigated. Then, the wave energy dissipation as wave passing over the breakwater is discussed based on the hydraulic coefficients of QCB and SCB. In irregular wav...  相似文献   

海上地震勘探GI枪子波数值模拟     

李国发  曹明强  陈浩林  倪成洲 《吉林大学学报(地球科学版)》2011,41(1):277-282

GI枪震源已经逐步成为海上地震勘探的主要激发方式。常规气枪只有一个腔室,而GI枪具有G腔和I腔2个腔室,能够较好地压制气泡振荡。基于自由气泡振动理论,分析GI枪的激发机制,在考虑气泡壁的热传导作用和流体粘度对气泡振动影响的基础上,建立了海上勘探GI枪子波数值模型,并对气泡的振动过程和远场地震子波进行了数值模拟。结果表明:当G腔内气体释放所形成的气泡体积达到最大时,I腔内气体的释放有效地抑制了气泡的收缩,气泡壁运动速度明显减小,气泡变得稳定;GI枪激发所产生的子波具有明显的峰值和较小的旁瓣,有利于高分辨率海上地震勘探。  相似文献   

海洋重力资料整理技术与软件实现     

刘展  白永良  张志珣  杨慧良  杜润林  史增园  张刚 《海洋地质前沿》2011,(9):60-64

针对海洋重力测量成果规范化整理与重力异常计算软件开发问题,重点讨论了重力掉格校正与测线文件获取的可视化方法;引入贝塞尔方法计算船速和航向,并进行厄特渥斯校正.在此基础上,依据海洋重力调查规范,基于图形可视化技术开发了一套具有人机交互功能的海洋重力资料整理软件.  相似文献   

地球非对称变形的最新观测证据   总被引：9，自引：0，他引：9  

黄立人  马宗晋  朱建新 《地震学报》2002,24(2):196-199

根据2001年3月IERS公布的全球近600个GPS站、SLR 站及VLBI站的站坐标、速度及它们的误差估计，研究了地球的现今非对称变形．结果表明，以赤道为界，北半球目前仍处于挤压变形中，而南半球则处于扩张变形中．若以90Ｅ 和90Ｗ 经线为界，则以180经线为中心线的太平洋半球处于挤压变形中，而以0经线为中心线的大西洋半球，则处于拉张变形中．这种变形再次证明地球处于双重非对称变形之中，而且，如果以6366740.0m作为理想地球平均曲率半径，根据空间大地测量结果算得的体积变化率达到0.6651012 m3/a．   相似文献   

Formation and evolution of petroliferous basins in African continent and their hydrocarbon distribution     

SUN Haitao  ZHONG Dakang  ZHANG Simeng  WANG Xingming.State Key Lab of Petroleum Resource  Prospecting  Faculty of Natural Resource  Information Technology  China University of Petroleum  Beijing  China.Exploration  Development Research Institute of Dagang Oilfield Company  PetroChina  Tianjin    China 《东北亚地学研究》2010,(1)

There are eighty sedimentary basins in five different types in African continent,i.e.craton sag basin,foreland basin,intermountain basin,passive margin basin and rift basin,which underwent the stress environment of stable depression-compression-extension.The first three types of basins had been intensely influenced by Hercynian and Alpine tectonic movement,while the later two types of basins always exist in a stable extension environment.Different basin evolution caused the obviously hydrocarbon distributio...  相似文献